JP3357260B2 - Circuit breaker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker capable of reliably discharging arc gas generated inside to the outside and effectively using an internal space.

[0002]

2. Description of the Related Art Circuit breakers are used for transmission and distribution lines and substation buses.
It is a switch for automatically shutting off the circuit when a short circuit fault occurs in a device or the like, and is also used for opening and closing the circuit in normal times.

FIG. 5 shows a structural diagram of a conventional circuit breaker.
The conventional circuit breaker includes a main circuit, an opening / closing trip mechanism 3 'for opening / closing the main circuit contact, a trip device 5', and a housing 6 'for accommodating these.

As shown in FIG. 5, the main circuit is composed of a power supply-side fixed contact stand 11 ', a fixed contact 12', a movable contact 13 ', a movable contact stand 14', a load-side fixed contact stand 15 ', and the like. I have.

The opening / closing trip mechanism 3 ′ is
By moving it in conjunction with ', the contact of the main circuit is opened and closed.

The trip device 5 'operates the opening / closing trip mechanism 3' with the operation handle 41 'or the like when it is necessary to cut off the circuit.

The housing 6 'serves as a container for the circuit breaker, and houses the main circuit, the opening / closing tripping mechanism 3', the tripping device 5 ', and the like. Have.

[0008] Inside the housing, there are contacts 12 'and 13' which repeat connection and disconnection, and when opening and closing, an arc gas is generated between the contacts 12 'and 13'. The arc gas is generated by being influenced by the circuit conditions on the power supply side and the load side, the shape and material of the contact, etc., but is not preferable, and it is necessary to take measures such as discharging the arc gas to the outside.

Conventionally, as a method of discharging the arc gas to the outside, the arc discharge hole 61 'of the housing 6 is provided, but the discharge passage inside the housing is not considered much.

[0010]

According to the present invention, as a result of conducting a number of experiments and the like on the discharge passage to the arc discharge hole of the housing and examining the discharge passage, the arc gas is effectively removed from the housing. And the negative effect on nearby components caused when discharging the arc gas can be prevented, and the space inside the circuit breaker can be effectively used. It is found out the shape of the discharge passage.

[0011]

SUMMARY OF THE INVENTION The present invention provides a main circuit having a power supply-side fixed contact block, a contact, a movable contact block, and a load-side fixed contact block, and opening and closing circuit contacts by rotating the movable contact block. In a circuit breaker including an opening / closing trip mechanism, a trip device for operating the opening / closing trip mechanism, and a housing , arc gas is introduced into an arc discharge hole of the housing.
It has a cylindrical arc discharge port,
Insulation for accommodating an arc chute that sucks and cools heat
A case, wherein the contacts are half-cut on a slope of a fixed contact base.
The arc discharge port in the axial direction.
The surface direction of the chute and the inclination direction of the
A substantially parallel circuit breaker.

[0012]

[0013]

[0014]

[0015]

According to the present invention, the insulating case is a circuit breaker accommodating the arc chute.

[0017]

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described. One embodiment of the circuit breaker of the present invention, FIGS.
This will be described with reference to FIG. FIG. 1 is an explanatory view of an embodiment of the circuit breaker of the present invention, FIG. 2 is an explanatory view of an example of a fixed contact block in the circuit breaker of the present invention, and FIG. FIG. 4 is an explanatory diagram of an example, and FIG. 4 is an explanatory diagram of an example of a magnetic trip device in the circuit breaker of the present invention.

The respective poles of the circuit breaker of this embodiment include a power-supply-side fixed contact stand 11 electrically connected to the power-supply-side terminal and a load-side fixed contact stand 15 electrically connected to the load-side terminal. The power-supply-side fixed contact stand 11, the load-side fixed contact stand 15, and the movable contact stand are provided at substantially point-symmetric positions with respect to the rotation center of the movable contact stand 14 as a movable conductor rotatably held. 14 forms a main circuit.

The power-supply-side fixed contact stand 11 is a power-supply-side movable contact
The load-side fixed contact stand 15 has a load-side fixed contact 12 at a position facing the load-side movable contact 13.

The fixed contact 12 is provided in the half blanking formed portions 111 and 151 on the slopes of the fixed contact stands 11 and 15.

The movable contact stand 14 has a power supply side movable contact and a load side movable contact 13 at point symmetric positions with respect to the center of rotation.

The movable contact stand 14 is mechanically connected to the opening / closing tripping mechanism 3 as an opening / closing tripping mechanism. When the opening / closing tripping mechanism 3 is turned on, the power supply side fixed contact stand 11 and the load side fixing are fixed. It rotates to the position where it electrically connects with the contact stand 15.

This main circuit is housed in a main circuit case 2 made of an insulator. In the state where the main circuit is housed in the main circuit case 2, the power supply side terminal portion of the power supply side fixed contact stand 11 and the load side terminal portion of the load side fixed contact stand 15 protrude from the main circuit case 2. Is located in the main circuit case 2 and is electrically insulated from the outside. Main circuit case 2
The holding member for rotatably holding the movable contact table 14 therein is also formed of an insulating material.

In the main circuit case 2, a high-temperature and high-pressure arc gas is generated between the fixed contact and the movable contact on the power supply side and the load side at the time of interruption. Therefore, the main circuit case 2 and the holding member are required to withstand the high-temperature and high-pressure arc gas, and polyester resin is used in consideration of the cost of the product. Note that any other resin, ceramic, or the like may be used as long as it is an insulating material that can withstand high temperature and high pressure arc gas.

Power supply side fixed contact block 1 in main circuit case 2
1. An arc chute (arc extinguishing device) is provided near the contacts of the load-side fixed contact stand 15 and the movable contact stand 14 to attract and cool the arc generated at the time of interruption. Further, in this embodiment, the arc discharge port 2 for discharging the cooled arc gas is used.
1 is provided in the main circuit case 2.

The arc discharge port 21 is provided on the power supply side, and is provided at a position avoiding a nearby zero-phase current transformer.

The half blanking molded parts 111, 1 provided with the contacts
51, the arc chute 22, the arc discharge port 21, and the arc discharge hole 61 are arranged to be substantially parallel.

The shape of the arc discharge port 21 is cylindrical, and when discharging the arc gas to the outside, turbulence is hardly generated, and the arc discharge port 21 has effects such as not adversely affecting the nearby contacts 12, 13 and the like.

The opening / closing trip mechanism 3 is mounted on the upper outside of the main circuit case 2 and is connected to a rotating arm of an insulator coaxially connected to the rotation axis of the holding member. As a result, the opening / closing trip mechanism 3 is provided outside the main circuit case 2 and is connected to the movable contact stand 14 via the insulator.

The opening / closing trip mechanism 3 is operated manually by the operating handle 41 to turn ON / OFF the main circuit, and when the current in the main circuit exceeds a predetermined value, the trip device 5 is opened.
The main circuit shuts off.

As shown in FIG. 4, the tripping device 5 includes a fixed core 5a provided inside the main circuit case 2 near the load-side fixed contact stand 15, and a fixed core 5a provided outside the main circuit case 2. A movable core 5b disposed to form a magnetic circuit between the movable core 5b and the transmission lever 5c as a transmission mechanism for transmitting the operation of the movable core 5b to the opening / closing trip mechanism 3.

When the current of the main circuit increases and exceeds a predetermined value (about 10 times to about 20 times the rated current), the magnetic flux generated around the conductor of the fixed contact stand 15 on the load side increases. When the magnetic force due to the magnetic flux overcomes the force of the spring urging the movable core, the movable core is attracted to the fixed core and moves, and the transmission lever 5c of the movable core comes into contact with the latch 3a to rotate the latch 3a. The main circuit is opened by the tripping operation of the opening / closing tripping mechanism 3. As a result, the circuit is shut off and a large overcurrent can be prevented from flowing to the load side.

In this embodiment, the fixed contact block 1 on the load side of the main circuit is used.
5 is provided with a current transformer for detecting a current flowing through the main circuit at a portion from the main circuit case 2 to the load side terminal, and an output of the current transformer is supplied to an overcurrent detection circuit provided above the current transformer. Supplied.

The overcurrent detection circuit is approximately 1.1 times the rated current.
An output is generated in a range of about 20 times based on a predetermined time limit characteristic. The output of the overcurrent detection circuit is supplied to a magnetic trip device 5 that releases the movable core attracted by the permanent magnet by reverse excitation. As such a magnetic trip device, for example, the one described in Japanese Patent Application No. 8-62449 can be used.

When the movable core of the magnetic trip device is released, it comes into contact with the latch portion to rotate the latch portion, and the main circuit is opened by the tripping operation of the opening / closing trip mechanism portion 3. As a result, the open circuit is interrupted and the overcurrent can be prevented from flowing to the load side.

The main circuit case 2, the opening / closing trip mechanism 3, the trip device 5, the current transformer, the overcurrent detection circuit, and the magnetic trip device are housed in a housing 6 having a main body case and a main body cover. .

In this embodiment, the movable contact and the fixed contact of the main circuit are housed in the main circuit case 2 formed of an insulating material that can withstand high-temperature and high-pressure arc gas. As long as it has, an inexpensive thermoplastic resin may be used. As such a thermoplastic resin, nylon or the like can be used.

The housing 6 is an insulating case 2 containing a main circuit.
, The opening / closing trip mechanism 3 and components such as the trip device 5 are housed to constitute a circuit breaker.
have. In the case of an earth leakage breaker, a zero-phase current transformer, an earth leakage detection circuit, and the like are further housed. The output of the leakage detection circuit may be supplied to a magnetic trip device dedicated to the leakage trip, or may be supplied to a magnetic trip device for overcurrent to share components.

The zero-phase current transformer detects an imbalance of current of each phase due to a ground fault or the like.

The discharge of arc gas in the circuit breaker of the present invention will be described with reference to FIG.

Inside the housing, there are contacts 12 and 13 that repeatedly connect and disconnect, and an electric current flows between the contacts 12 and 13 when opening and closing, so that arc gas is generated. I do. In this embodiment, various measures are taken to discharge the arc gas to the outside.

The main circuit is housed in an insulating case having an arc discharge port for guiding arc gas to an arc discharge hole of the housing. Thus, the arc gas generated between the contacts 12 and 13 of the main circuit does not adversely affect components outside the insulating case.

The arc discharge port is provided on the power supply side. On the power supply side of the insulating case 2, a zero-phase current transformer is arranged as a component in the case of an earth leakage breaker. On the load side, an overcurrent operation device 7 having an overcurrent detection unit and a transmission mechanism is arranged. It takes up more space than the power supply.
Therefore, in order to use the space of the insulating case 2 effectively, it is preferable to provide the arc discharge port 21 on the power supply side.

The arc discharge port has a cylindrical shape. Thus, when the arc gas generated inside the insulating case is discharged out of the insulating case, it is smoothly discharged without generating turbulent flow due to a chimney effect.

The housing houses a zero-phase current transformer on the power supply side in the case of an earth leakage breaker, and the arc discharge port of the insulating case is provided at a position avoiding the zero-phase current transformer. Connected to the hole. This allows the arc gas to be smoothly discharged from the inside of the insulating case to the outside of the housing, without adversely affecting components such as the zero-phase current transformer inside the housing, and effectively using the space inside the housing. be able to.

As shown in FIG. 2, the contact is provided at a half-blanked portion on the slope of the fixed contact stand. Thereby, the flow path of the arc gas generated from the contact of the main circuit is easily aligned in the direction of the discharge port of the insulating case, and flows smoothly.

The insulating case houses the arc chute. Thus, the arc gas generated from the contact of the main circuit flows smoothly toward the discharge port of the insulating case using the arc chute.

The axial direction of the arc discharge port and the arc chute
Plane direction and the inclined direction of the half blanking part are substantially parallel
And As a result, when the arc gas is discharged to the outside , turbulence hardly occurs, and it is unlikely to adversely affect components arranged in the vicinity.

[0050]

According to the present invention, it is possible to effectively discharge the arc gas to the outside, and it is possible to prevent adverse effects on nearby components caused when the arc gas is discharged to the outside, Furthermore, there is an effect that the space inside the circuit breaker can be effectively used.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an embodiment of a circuit breaker of the present invention.

FIG. 2 is an explanatory diagram of an example of a fixed contact stand in the circuit breaker of the present invention.

FIG. 3 is an explanatory diagram of an example of an arc-extinguishing chamber in the circuit breaker of the present invention.

FIG. 4 is an explanatory view of an example of a magnetic trip device in the circuit breaker of the present invention.

FIG. 5 is an explanatory view of a conventional circuit breaker.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Power supply side fixed contact stand 111 Power supply side fixed contact half blanking forming part 12 Fixed contact 13 Movable contact 14 Movable contact base 15 Load side fixed contact stand 151 Load side fixed contact half blanking forming part 2 Main circuit case 21 Arc discharge port 22 Arc Chute 3 Opening / closing trip mechanism 41 Operating handle 5 Tripping device 6 Housing 61 Arc discharge hole

Continued on the front page (72) Inventor Hidetaka Fujita 46-1 Tomioka, Nakajocho, Kitakanbara-gun, Niigata Industrial Machinery Division, Hitachi, Ltd. (72) Inventor Toshihiro Sekiguchi 46-1 Tomioka, Nakajo-cho, Kitakanbara-gun, Niigata Hitachi, Ltd., Industrial Equipment Division (72) Inventor Mangeo Watanabe 46-1, Tomioka, Oji, Nakajo-cho, Kitakanbara-gun, Niigata Prefecture Inside the Industrial Equipment Division, Hitachi, Ltd. (56) References JP-A-6-28964 (JP, A) JP-A-63-301444 (JP, A) JP-A-53-141473 (JP, A) JP-A-1-120441 (JP, U) JP-A-55-50565 (JP, U) JP-A-61 −49948 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01H 73/18 H01H 73/36

Claims (1)

(57) [Claims] 1. A power supply side fixed contact block, a contact, a movable contact block and the like.
And a main circuit having a fixed contact block on the load side andTheThe movable contact block
Open / close trip to open / close circuit contacts by rotating
Mechanism,TheA trip device that operates the opening / closing trip mechanism
And a circuit breaker comprising a housing,A cylindrical arc for guiding arc gas to the arc discharge hole of the housing;
Has a gas discharge port, and sucks the main circuit and arc gas.
Equipped with an insulating case for storing the arc chute to be cooled
e, The contact is provided on a half-blanked molded portion on the slope of the fixed contact stand.
And The axial direction of the arc discharge port and the plane direction of the arc chute
And the inclination direction of the half blanking formed part was substantially parallel. This
And a circuit breaker.